This invention relates to the design of the inner wing region of a forward swept wing for transonic flight regimes. More particularly it relates to the design of the wing sections towards the wing root which suppresses the tendency of the isobars to desweep over the inner wing, so maintaining shock wave sweep far inboard.
Forward swept wings have some potentially attractive aerodynamic features including a higher geometric sweep at the shock position, `good` stalling characteristics due to the more highly loaded inner wing, and lower wing root bending moments leading to a lighter wing structure than the `equivalent` aft swept wing. They do have some disadvantages, not the least of which is the aerodynamic design of the inner wing region. The outer wing design is fairly straight forward and it is not difficult to maintain well swept isobars. Over the inner wing, however, there is a tendency for a very strong, unswept shock to form at high subsonic Mach numbers and at high lift coefficients.